Holes are being drilled in the Alpine Fault in the South Island to learn more about what will happen when it ruptures.
The Alpine Fault is the longest active fault in the country, extending 650km from Blenheim to Milford Sound.
The research is taking place 20km north of Franz Josef on the West Coast.
Principal scientist for GNS Science Rupert Sutherland says a 100-metre-deep hole has been drilled and work will begin on a second hole 200 metres deep on Tuesday.
Mr Sutherland says the research involves three stages - the first drilling a core of rock to reveal the structure of the fault.
Scanning equipment will then be lowered into the hole to provide various information about the fault, including the way it has fractured.
Finally, permanent monitoring equipment will be lowered to create a deep fault zone observatory, enabling GeoNet to record earthquakes that are 100 times smaller than it can currently detect.
Mr Sutherland says the research is not aimed at improving the ability to predict large earthquakes.
It was commissioned before September's damaging 7.1 magnitude Canterbury quake and is funded by organisations throughout the world.
